1. Field of the Invention
The present invention relates to a method of manufacturing a circuit board, and more particularly, to a method of manufacturing a circuit board used to easily etch a conductive layer.
2. Description of the Related Art
Electronic products include many components that are usually installed in a circuit board manufactured by forming a conductive layer on a substrate including an insulator and forming a circuit pattern in the conductive layer. The circuit board includes a base substrate in which an inner circuit is formed, an interlayer insulating layer, an outer circuit layer, a resist layer, and the like.
The circuit board also includes an exposed conductive layer for connection with a semiconductor, or the like. The conductive layer may include copper, but the copper may corrode or be easily oxidized. Thus, the copper is plated with nickel, and then plated again with thin gold.
When a predetermined pattern is formed on the circuit board, a conductive layer including gold is etched using photolithography. In particular, when an etch back process for etching a lead line portion to which a voltage is applied is performed in order to perform electroplating, a process for etching a conductive layer affects the quality of the circuit board. However, it is difficult to etch a conductive layer including various metals such as gold, nickel, copper, and the like.
During the process for etching the conductive layer, impurities may be generated, or the conductive layer may be overetched or underetched. Thus, it has been difficult to improve the quality of the circuit board.